Door latch



Sept. 5, 1967 R. s. LINT DOOR LATCH Filed April 12, 1966 ROBERT S. LINT INVENTOR.

ATTORNEYS United States Patent 3,339,958 DOOR LATCH Robert S. Lint, 7800 Perimeter Road 8., Seattle, Wash. 98108 Filed Apr. 12, 1966, Ser. No. 542,078 3 Claims. (Cl. 292-169) This application is a continuation-in-part of my oopending application Ser. No. 443,256, filed Mar. 29. 1965. which is in turn a division of my Patent No. 3,179,459, issued Apr. 20, 1965.

The present invention relates to door latches of the general type in which a slide bolt is retracted by turning of a handle in opposition to a spring and is returned by the spring to an extended position.

An important object of the invention is to provide a latch that is not only of simple and economical construction and easily installed, but which is quiet in operation and can be readily adjusted to vary the speed of bolt extension.

Another object is to provide a latch that can be used on several thicknesses of doors without modification.

Other more particular objects and advantages of the invention will, with the foregoing, appear and be understood in the course of the following description and claims the invention consisting in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawing:

7 FIG. 1 is an exploded perspective view of a latch mechanism embodying the present invention; and

FIG. 2 is a horizontal sectional through the latch installed in a door.

Referring to the drawings, the latch of the present invention has a bolt and rollback assembly 10 presenting a square-bodied shaft 11 threaded at its ends to extend into a pair of handles 12 and receive nuts 13. The handles 12 are in turn journal mounted in escutcheons 14, and as part of the invention, washers 15 sleeved on the spindle 11 serve as bearings between the handles and escutcheons, and may be made as an integral part of the handles when the handles are formed of a suitable plastic bearing material such as nylon.

The assembly 10 may be of the type disclosed in my prior Patent No. 3,179,459, and namely one having its slide bolt 16 formed with inner diverging fork arms 17 each of which is longitudinally slotted at 18 and has an abutment at its free end defining the respective end wall of the slot. A pair of oppositely extending rollbacks 21 project through the slots 18 froman integral boss 22 which is sleeved on the shaft 11 and extends endwise of the sides of the rollbacks 21 to fit within a pair of spaced forks 23. These forks are presented by a head 24 on one end of a guide rod 25 having its other end projecting between the fork arms 17 on the bolt 16 into a bore 26 formed in the bolt along part of the length thereof. A bolt-return compression spring 27 is sleeved on the guide rod 25 to seat against the fork head 24 and bear against the closed end wall of the bore 26. This spring force yieldingly urges the rollbacks 21 against the abutments 20 at the free ends of the fork arms 17.

The escutcheons 14 are each formed at the back with a boss for interfitting with the respective end portion of a round opening 30 bored through the swinging door D adjacent the jamb J to receive the rollback mechanism. This opening 30 is intersected by a horizontal radial hole 31 that extends to the edge of the door facing the jamb and is somewhat larger in diameter than the bolt 16 so as to permit the bolt, rollbacks 21, guide rod 25, and spring 27, to be installed as a unit in the door by inserting the bolt through the opening 30 into the inner end of the hole 3,339,958. Patented Sept. 5, 1967 31 with the unit slightly cocked toward one face of the door until the fork arms 16 reach the rim of the opening 30 to clear the door face and become completely housed in the opening 30. Then a bushing 32 is force-fitted in the hole 31 through the outer end thereof to provide a slide journal for the bolt 16. The jamb J is fitted with a strike plate 33 opposite the hole 31 having a keeper opening to receive the bolt when extended.

Returning to the escutcheons 14, the outer faces thereof may be somewhat dished, and each is formed with a center through opening 34 which is somewhat larger in diameter than the diagonal dimensions of the square crosssection of the spindle 11. The outer face of the escutcheons is centrally counter-bored to provide annular bearing seats 35 surrounding the center opening 34 in the escutcheons for receiving the washers 15. These washers have a square center opening to sleeve on the spindle 11 and have a boss extension 15a at the back that mates with the center opening 34 in the escutcheons.

The depth of the counter-bores to the bearing seats 35 is greater than the thickness of the main body of the washers 15 so as to provide space for housing a free end portion of flat-headed stems 36 projecting from the back of the handles 12. It will be noted that the handles are hollow to house the outer threaded ends of the spindle 11 and the associated nuts 13, and that the stems 36 have a bore of square cross-section to sleeve onto the shaft. The handle cavities are closed with cover plates 37 which may be retained by snap rings 38.

It will be apparent that after the bolt and rollback mechanism have been inserted as a unit in the door in the manner above described, assembly of the latch can be readily completed, after inserting the spindle 11 through the rollback .boss 22, by fitting the escutcheon bosses in the hole 31 in the door, sleeving the washers 15 and handles 12 onto the ends of the shaft, screwing on the nuts 13, and then applying the cover plates 37.

The washers 15 are made of nylon or some other suitable durable bearing material of similar characteristics whose frictional resistance to turning relative to the seats 35 can be varied in a controlled manner by selectively changing the axial pressure on the washers through adjustment of the nuts 13. These nuts are preferably selflocking, as for example, the plastic insert type; so that they will hold adjusted positions.

For quiet operation it is preferred that the strike plate 33 be formed of nylon or some other suitable synthetic plastic material which is strong, tough, durable, and has superior impact resistance, and yet will be quiet during impact. With the described arrangement the handles 12 and escutcheons 14 can be metal or plastic. If the handles are made of nylon or some other suitable bearing material, the washers 15 can be incorporated on the stems of the handle as an integral part thereof. It has been found that the shaft 11 may be formed vfrom an aluminum alloy bar stock having good corrosion resistance and torsion strength and the guide rod 25 and head 24 may be molded as a one-piece plastic member.

Because the nuts 13 can be minutely adjusted on the spindle 11, the frictional resistance of the washers 15 to turning on the seats 35 during extension of the bolt 16 responsive to the return action of the spring 27 can be adjusted so that the bolt will extend (after retraction for opening of the door) smoothly without a noisy snap-back, and in fact, can be adjusted so that the bolt will extend in visual slow motion. This adjustment is thus very fine and the setting can be easily changed at will after the latch has been installed, merely by removing one of the cover plates 37 to gain access to one of the nuts 13. Regardless of the adjustment of the nut pressure, the boss portion 15a of the washers 15 working in the openings 34 provides an excellent bearing for the spindle 11 in the escutcheons 3 and transfers the thrust exerted by the spring 27 against the shaft, through the escutcheons 14 to the door.

It is important to note that the above described latch can be used without modification on a wide selection of door thicknesses since there is provided a wide range of adjustment of the nuts 13 along the shaft 11.

It is believed that the invention will have been clearly understood from the foregoing detailed description of the now-preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.

What is claimed is:

1. A latch assembly comprising, a slide bolt slidable between extended and retracted position, spring means urging said bolt into extended positions, rollback means including a boss having a non-circular opening for retracting said bolt in opposition to said spring means, a pair of escutcheons with alined round central Openings surrounded by a pair of recessed annular seats, a non-circular spindle extending freely through said central openings and rollback boss for operating said rollback means responsive to turning of the spindle, said spindle being slidably adjustable along its longitudinal axis relative to said rollback means, handles and bearing means slidably sleeved on the spindle to turn in unison therewith, said bearing means being seated against said recessed annular seats and having respective boss-like protrusions extending into and having a bearing interfit with said central openings in the escutcheons and in substantial contact with .4 said rollback boss, means resisting outward endwise movement of one of said handles relative to the respective end of the spindle, the other end of the spindle being threaded, a nut screwed on said threaded end of the spindle and bearing against the other handle to adjustably hold said bearing means against said seats by pulling said handles toward one another, said other handle having an outwardly opening cavity housing said nut, and a removable cover plate on said other handle for said cavity.

2. A latch assembly according to claim 1 in which said bearing means comprises a pair of washers sleeved on the spindle.

3. A latch according to claim 2 in which said handles have rearwardly projecting fiat-headed stems pressing against said washers and occupying part of the depth of the recesses to said seats.

References Cited UNITED STATES PATENTS 435,250 8/1890 Sampson 292-357 1,362,669 12/1920 Bradshaw 292-169 1,487,975 3/1924 Riddick 292350 X FOREIGN PATENTS 476,167 8/1951 Canada.

648,433 3/ 1935 Germany.

MARVIN A. CHAMPION, Primary Examiner.

EDWARD C. ALLEN, Examiner.

I. R. MOSES, Assistant Examiner. 

1. A LATCH ASSEMBLY COMPRISING, A SLIDE BOLT SLIDABLE BETWEEN EXTENDED AND RETRACTED POSITION, SPRING MEANS URGING SAID BOLT INTO EXTENDED POSITIONS, ROLLBACK MEANS INCLUDING A BOSS HAVING A NON-CIRCULAR OPENING FOR RETRACTING SAID BOLT IN OPPOSITION TO SAID SPRING MEANS, A PAIR OF ESCUTCHEONS WITH ALINED ROUND CENTRAL OPENINGS SURROUNDED BY A PAIR OF RECESSED ANNULAR SEATS, A NON-CIRCULAR SPINDLE EXTENDING FREELY THROUGH SAID CENTRAL OPENINGS AND ROLLBACK BOSS FOR OPERATING SAID ROLLBACK MEANS RESPONSIVE TO TURNING OF THE SPINDLE, SAID SPINDLE BEING SLIDABLY ADJUSTABLE ALONG ITS LONGITUDINAL AXIS RELATIVE TO SAID ROLLBACK MEANS, HANDLES AND BEARING MEANS SLIDABLY SLEEVED ON THE SPINDLE TO TURN IN UNISON THEREWITH, SAID BEARING MEANS BEING SEATED AGAINST SAID RECESSED ANNULAR SEATS AND HAVING RESPECTIVE BOSS-LIKE PROTRUSIONS EXTENDING INTO AND HAVING A BEARING INTERFIT WITH SAID CENTRAL OPENINGS IN THE ESCUTCHEONS AND IN SUBSTANTIAL CONTACT WITH SAID ROLLBACK BOSS, MEANS RESISTING OUTWARD ENDWISE MOVEMENT OF ONE OF SAID HANDLES RELATIVE TO THE RESPECTIVE END OF THE SPINDLE, THE OTHER END OF THE SPINDLE BEING THREADED, A NUT SCREWED ON SAID THREADED END OF THE SPINDLE AND BEARING AGAINST THE OTHER HANDLE TO ADJUSTABLY HOLD SAID BEARING MEANS AGAINST SAID SEATS BY PULLING SAID HANDLES TOWARD ONE ANOTHER, SAID OTHER HANDLE HAVING AN OUTWARDLY OPENING CAVITY HOUSING SAID NUT, AND A REMOVABLE COVER PLATE ON SAID OTHER HANDLE FOR SAID CAVITY. 